Machine for cutting nozzles for turbines and the like.



A. E. CHERNAGK. MACHINE FOR CUTTING NOZZLES FOR TUBBINES AND THE LIKE.

APPLIOATION FILED MKY13, 1908.

Patented July '6, 1909.

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APPLICATION FILED MAY 13, 1908. 927,450, Patented July 6, 1909.

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ABRAHAM E. GHERNAGK, OF BOSTON, MASSACHUSETTS.

MACHINE FOR CUTTING NOZZLES FOR TURBINES AND THE LIKE.

Specification of Letters Patent.

Application filed May 13, 1908.

Patented July 6, 1909.

Serial No. 432,657.

T 0 all whom it may concern:

Be it known that I, ABRAHAM E. CHER- NACK, a subject of the Emperor of Russia, and a resident of Boston, in the county of Suffolk, in the State of Massachusetts, have invented certain new and useful Improvements in Machines for Cutting Nozzles for Turbines and the Like, of which the following is a. specification.

My invention is particularly designed for use in cutting or broaching out the nozzle holes of steam turbines, which holes are tapering and of irregular crdss-section at different points in their length, but my invention is also applicable to the cutting of tapering holes for any purpose.

In the accompanying drawings Figure 1 is a front elevation of a machine embodying my invention; Fig. 2 is a side elevation partly in section; Fig. 2 is a plan view of a rocking lever; Fig. 3 is a sectional view showing a suitable operating mechanism; Fig. 1: is a sectional. diagrammatic view; Fig. 5 is a cross section through the finished nozzle hole at 5-5, Fig. 4c; Fig. 6 is a crosssection at (S 6, Fig. 4; Fig. 7 is a face view of the outlet end of the nozzle at 7-7, Fig. 4; Figs. 8 and 9 are cross sections of the cutting tools and expanding wedge corre spending with Figs. 5 and 6, respectively; and Fig. 10 is a sectional view of a modification.

My invention will be better understood if I first explain the peculiar shape of nozzle holes in steam turbine rings, for the cutting of which my machine is especially designed. Fig. 4: is a diagrammatic section through a portion of turbine ring at one of the nozzle holes in process of formation. At the entrance end for the steam a hemispherical hole cc, whence the passage or nozzle leads diagonally at 3 gradually increasing in cr0ss-section, and gradually changing from a round at 5-5 to a round cornered rectai'igle at 6-6 and 77. In the formation of these nozzle holes a cylindrical hole is first drilled or otherwise formed through the center line of the desired nozzle and the cup a: is formed, and then by means of my machine, which I will now describe, I cut out the hole to the irregularly shaped taper indicated by the views, Figs. 4 to 7, the dotted. cross hatching in Fig. l indicating the metal which has to be cut away in this ope 'ation.

The essential working elements of my machine are one or more reciprocating cutting tools and a movable backing member for expanding the cutting tool or tools against the wall of the hole, said backing member presenting a bearing face to the cutter tapering or inclined to the line of movement of the backing member, and means for reciproeating thelatter between the cutting strokes. 13y preference I employ two such cutters to breach out the opposite sides of the hole at 1 the same time, and for the expanding means 1 preferably use a tapering wedge between the two cutters and means for intermittently reciprocating that wedge to press the two cutters outwardly during their cutting stroke, and free them on the return stroke.

Referring to Figs. 1, 2 and 3, A and A are the two reciprocating cutters which are shown as dqaending vertically (Fig. 2) and are carried by two tool carriers, 17, 17, adapted to slide upon two dovetailed upright guides 18. These guides are in turn mounted upon two horizontal slides 20 in dovetailed guides 2:- (Fig. 2) in the standard or frame S, and the slides 20 are 11011- mally pressed toward each other by fiat" To keep the cutters and wedge piece in the same plane, it is preferaliile to make their meeting faces of slightly V-section, at least at some parts (Figs. 8 and 9). A

The expanding wedge piece B is removably attached at its upper end to a block 29 reciprocating in a guide 30 on the top of the frame of the machine.

\Vhile variously constructed mechanism may be employed for actuating the cutters A, 1: and expansion piece B, I have shown in the drawings certain devices which may be employed for the purpose. Thus each slide 17 may be connected by links 16, universally jointed, to the forked end of a rocking lever 12, (Fig. 2) which is pivoted at 13 to posts on the top of the frame of the machine. The rear of the rocking lever 12 is connected by a rod 11 (Fig. 2), to a crank pin 10 on a disk 9 (Figs. 2 and 3). This disk 9, which also serves as a cam to actuate the expansion piece B, is driven by suitable gearing from the driving shaft a with fast and loose pulleys, l, 2. This gearing may comprise a pinion 5, on the driving shaft, a gear 6, on countershaft 4i, pinion 7 and gear 8, which last is secured to the disk 9 or the shaft which carries it.

The cam outline of the disk will be seen on reference to Fig. 2 and it is arranged to act on an antifriction roller on the end of a bell-crank lever 31 pivoted to the frame and connected by a rod 32 (Fig. 2), to one end of a rocking lever 33. A suitable spring 35 may be provided to act in opposition to the cam. The rocking lever 33, which is pivoted to the frame at 14, is pivotally connected at St to the block 29 carrying the expansion piece B. The parts are so timed in their operation that while the cutters A and A are descending, or in other words on their return stroke, the expansion piece B is held in its upper position, and the cutters are then more or less free of the work. Just as the cutters are about to begin their upstroke, which is the cutting stroke, the wedge piece B descends to its lower position and thereby forces the cutting edges of the tools outward into cutting engagement with the walls of the metal. The teeth of the cutters are set to cut on the upstroke of the tools. (hen the cutters have reached the top of their stroke the wedge piece is caused to ascend again to its upper position, to free the cutters.

The work table F may be provided with any well known or suitable feed to be actuated by hand or automatically. In the drawings, for the sake of illustration, the work table F is shown as mounted to be adjustable horizontally upon a plate E, which in turn can be adjusted vertically on guides E on the frame to feed the work up to the cutting tools, by means of a suitable feed screw D.

In the case of working on sections of rings for steam turbines, a special work holder C, Fig. 1, is provided to support the work W at the desired angle. I prefer to make the blank 7 with butts to, Fig. 1, where the nozzles are to be cut out, so as to give a substantially equal support to the two cutters A, A while cutting out the hole, but the butt thus left can be planed ofl' afterward.

The cutting edges of the two cutters are semi-circular toward their forward ends, and generally merge into rectangular outline, as will be understood by reference to Figs. 8 and 9, but this change in cross section is not the same in the two cutters, because it will be seen from Fig. 4 that one side (the short side) of the finished nozzle hole has a quicker inclination than the other, and the two tools must be shaped accordingly. I do not however confine myself to any particular shape of cutting tools. In fact to cut out one hole, different cutters may be employed, as for example, a pair of cutters with rounded cutting faces to give the general tapering form to the hole, and then another pair of cutters may be substituted for them to finish the rectangular corners of the larger end of the hole. So also, I do not confine myself to the use of a pair of cutters. For example, with large tapering holes, as many as four cutters A A (Fig. 10) may be employed with an intermediate expansion or wedge piece B having the section of a cross.

I claim as my invention 3,

1. A machine for cutting out tapering holes, comprising a cutter and means for reciprocating it, in combination with a movable backing member for the cutter presenting a bearing face to the cutter inclined to the line of movement of the backing member and means for reciprocating the latter between the cutting strokes.

2. A machine for cutting out tapering holes, comprising a pair of cutters and means for reciprocating the same, in combination with a movable intermediate backing member for the cutters presenting bearing faces to the cutters inclined to the line of movement of the backing member and means for reciprocating the latter between the cutting strokes.

3. A machine for cutting out tapering holes, comprising a cutter and means for reciprocating it, in combination with a movable backing member for the cutter presenting a bearing face to the cutter inclined to the line of movement of the backing member, means for reciprocating the latter between the cutting strokes, and means .for feeding the work to the cutter.

t. A machine for cutting out tapering holes, comprising a pair of cutters and means for reciprocating the same, in combination with a movable intermediate backing member for the cutters presenting bearing faces to the cutters inclined to the line of movement of the backing member, means for reciprocating the latter between the cutting strokes, and means for feeding the work to the cutters.

5. A machine for cutting tapering holes, comprising a pair of cutters and their carriers and angularly adjustable guides for the latter, in combination with means for reciprocating said cutter carriers, a wedge piece between the cutters and means for intermittently reciprocating the Wedge piece, substantially as described.

6. A machine for cutting tapering holes, comprising a pair of cutters and their carriers, angularly adjustable guides for the latter, a pair of slides on which said guides are mounted, and springs to press the slides toward each other, in combination with means for reciprocating the cutter carriers, a Wedge piece between the cutters and means for intermittently reciprocating the Wedge piece.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing Witnesses.

ABRAHAM E. OHERNAGK.

Witnesses WVALTER ABBE, I-Inennr Hon son. 

